Abstract: The invention is a system and method for detecting whether a piece of direct mail marketing has been read by a recipient. The invention includes a novel envelope with an embedded sensor to detect whether it has been opened and a transmitter to send information from the sensor to a receiver, which in turn sends the information to a central computer. In the preferred embodiment this information is aggregated in a central computer and can then be analyzed to provide information about particular recipients, a group of recipients or about the effectiveness of a particular direct mail campaign.